Chapter pages 33-60

delayed return or even loss of functional capacity. Many such wounds
will require revision
at a
later time with the patient having needlessly been denied the appropriate care. Wounds that are
assessed as needing excision and closu¡e should undergo removal as soon as possible- Jackson and
associates demonstrated in the 1950s the feasibility of burn wound excision and closrue in wounds
of up to 30% TBSA.e5 present day management
of
bum patients has extended this approach to all
but the most massive of burn injuries.
If
the patient is otherwise stable bum wound excision can be carried out within a matter of hours
post-injury. In the patient with a small burn delay is often related to scheduling of the operating
room and the surgical team. Timely excision for the patient with a small burn reduces the period
disability and the overall cost of the injury. In patients with
a large burn wound the
of
timing and
extent of the surgery is based on the patient's relative physiologic stability and his capacity to
large
undergo a major operative procedure. Early burn wound excision and closwe in patients with
wounds shofens the length of hospitalization,reduces cost, and favorably impacts overall bum
problems
mortality.%'e7 The presence of the bum wound is the primary stimulus for the ongoing
facing the burn patient. Closwe of the burn serves to ameliorate much of the post-burn
pathophysiology and is one of the most effective means by which to improve a burn patient's
outcome-
Wounds that are small in size or linear in shape can be managed by excision of the burn and
primary woqnd closure. This is of use in burns of the upper inner arm in the elderly,localized
bums of a pendulous breast,.aþ{ominal burns, buttock injuries and thigh burns. Primary wound
closure can also be achieved in some wounds with local tissue transfer techniques. This approach
works quite well when these wounds are excised early before significant microbial colonization
of
the wound occurs. In such cases the burn is transformed into a healing surgical incision and
creation of a skin graft donor site is avoided.
In selected
cases the
injury may be of such
a nature that amputation
of the bumed part is the most
the
appropriate plan. In the patient with significant multi-system trauma the expeditious removal of
bum injury might be seen
as
lhe best option for the patient's overall survival. In a recent report
Santaniello and associates found that the mortality in trauma victims with significant burn injuries
and trauma was2ï.3o/owhereas in patients with burns only it was 9.8olo and in patienls with trauma
53
only it was 4'3o/o-et The management of these challenging patients requires
a coordinated wellconceived plan of care that accounts for all of the patient's injuries
and integrates the treatment
needs of each inj.r.y to achieve an overall satisfactory outcome.
A mangled extremity, which
has
also sufTered a severe burn that is deemed non-salvageable, should
undergo early amputation.
It is
not necessary to extend the åmputation to a level that allows closure
with unburned tissue. If viable
muscle is available to close the amputation site that wo¡nd bed can be
resurfaced with an
autogenous skin graft. A grafted amputation site can, with a modern
prosthesis, fi¡nction as a
durable stump. In a patient who is paraplegic and zuffers an extensive
deep lower extremity burn
injury amputation can be a viable alternative to excision and grafting.
A similm option may need to be considered for the patient in whom significant preexisting
peripheral vascula¡ disease makes the tikelihood of a healed and
functional extremity highly
unlikely' This unfortunately has become an all too frequent occurrence
in the ca¡e of elderly burn
patients who have progressive complications from long standing
diabetes mellitus. The amputation
level should be that which will maintain maximum function. This might
be a trans-metatarsal or
Chopart-type amputation in patients with injuries of the distal foot. In patients
confined to a wheel
chair who have injuries to the leg a through-knee amputation as opposed
to an above-knee
amputation provides a weight-bèaring platform for sitting. In the patient
in whom the initial insult
represents a deep composite injuty repeated failed attempts at salvage
are not in the patient,s
ultimate best interest- Such wounds often become infected and tissue that
could have been
preserved now must in the end be sacrificed with the functional
end result less than that which
would have occurred with early amputation.
Excision and grafting will be required for wounds not amenabte primary
to
closure. The extent of
the procedure that a patient can undergo is related to the patient's
age, physiologic status and skill
of the operating team- A 17% surface area burn should be a universally
survivable injury in a
seventeen year old patient while in a patient in the eighth decade
of life the mortality can easily
be
50%' An otherwise healthy individual with available donor sites
can well tolera te aZ0-25Tototal
body burn excision and autografting in one procedure- Implicit in
this approach is the use of
experienced operating teams, an anesthesiologist who thoroughly
understands the unique problems
of the patient with a major body surface area burn, and an operating room
firlly equipped to treat
such a patienl, as well as ready availability of blood products
and the capacity to care for the
patient post-operatively- A patient having this extent of surgery
in essence undergoes a doubling of
34
the surface area of "injury"-the now excised and grafted wound along with the paltial thickness
wound produced by the donor site. In patients with wounds of a larger size (>3O'ÂTBSA) or those
who cannot tolerate a single procedure to achieve closure, staged excision of bumed tissue is
performed and the resulting wounds are closed with available cutaneous autografts or a biologic
dressing.ee
The technique of burn wound excision is based on the depth of the wound and anatomic site to be
excised. Excision of deep partial thickness wounds to the level of a uniformly viable bed of deep
dermis, by the tangential technic pioneered by Janzekovic, and immediate coverage with cutaneous
with
autograft results in rapid wound closure with a typically excellent result.rm This can be done
an unguarded V/eck knife, a Goulian guarded Weck
knife, a hand held dermatome or by using a
age
powered dermatome set at .0016-.0030 of an inch depending on the area to be excised and the
the knife as
and gender of the patient. Optimally, the desired wound bed is achieved in one pass of
will be
evidenced by diffuse bleeding. If that end point is not realized another pass of the knife
and
needed. A frequent error is attempting this technique in wounds of an inappropriate depth
with a poor take
assuming that punctuate bleeding indicates a viable bed. Such wounds will heal
the
of the grafted skin as the bed contains marginally viable tissue incapable of supporting
to be doing well
cutaneous autograft. These wounds at the initial graft dressing change may appear
employed
only to fail at 5-10 days post-operatively. Tangential excision as originally reported was
wound that is
early in the first week post-burn, however it can be successfully applied any time to a
of blood
not infected or heavily colonized. During the performance of this procedure the amount
clysis
loss can be minimized with the use of a tourniquet on extremity burns or sub'eschar
these
containing epinephrine. The decision that the depth of the excision is satisfactory with
most
adj¡ncts will be based prirnarily on the appearance of the wound, an appreciation of which
experienced burn suigeons have had to learn to some degree through trial and eror-
A modification of tangential excision is wound excision via layered escharectomy. Using this
of
technique the wound is sequentially excised to a viable bed of subcutaneous tissue and elements
part
deep dermis particularly at the wound margin. This allows relative preservation of body
contour, a graft with ultimately more pliability, decreased limb edema and a cosmetically more
wound
acceptable transition at the juncture of the grafted wound with the unburned skin of the
margins.
35
An alternative to layered excision is to excise the wound
with a scalpel or electocautery. using
knife excision the wound is excised to the muscle fascia
or to viable deep subcutaneous tissue.
Bleeding can be significant with zuch procedures, therefore
the excision and control of bleeding
must be done efficiently. The use of electrocautery to perform
the dissection limits the blood
loss
without compromising the recipient graft site. Imperative
with electrocautery excision into the deep
fat is avoidance and limitation of thermal inju.y to the
wound bed, which
will compromise the
"take" of the applied skin graft' The use of the cutting
mode with rapid dissection is necessary. In
cases where excision to fascia has been performed
the viability of the fascia
should be assessed.
The surgeon must determine if the fascia requires removal
and the underlying muscle used as the
graft bed' In the performance of fascial excisions
caution should be exercised during the dissection
to avoid entrance into a joint or bursa and injury of extensor
tendons in the hand or the Achilles,
tendon at the ankle.
The blood loss occurring with bum wound excision is
related to the time of excision post bum, the
area to be excised' the presence of infection, and
type of excision, i.e. fascial or tangential. Donor
sites can also represent a significant portion of the blood
loss- The use of the scalp or previously
harvested donor sites is associated with increased bleeding,
Th" quantity of blood loss has been
estimated to range from 0-45 to 1.25-mllcm2 bum area excised.¡or
Adjunctive measures that can be
used to control blood loss include elevation of limbs undergoing
excision, applications of topical
thrombin and/or vasoconstrictive agents in solutions to the
excised wound and donor site, clysis of
graft
skin
harvest sites and./or the eschar prior to removal, and
application of toumiquets. Spray
application of fibrin sealant can also reduce bleeding from
the excised wound after release of the
toumiquet' Blood loss will be compounded if the patient has become
coagulopathic,
hypothermic or acidotic dwing the procedure. Perioperative
cold sbess, which may induce
hypothermia, can be reduced by maintaining the temperature
of the operating room between 30 and
32 degrees centigrade and by using warmed fluids for wound
irrigation. The harvest, application,
and postoperative care of split thickness skin graffs
and skin graft donor sites are the same as for
any other surgical patient.
l
Grafting of the bum wound is usually done at the time
of excision. However, there are instances
where it advisable to stage the skin grafting procedure.
The surgeon must be aware of the patient,s
slalus throughout the surgical procedure and ifnecessary
reassess the extent ofthe plarured
procedure' It may be best to perform the excision
only and stage the timing of skin grafl
36
application. Additionally, if the wound bed is suspect as to its viability then only excision should
be performed. The wound can be dressed
with a 5% zulfamylon solution dressing or coveredwith
allograft skin or any of several biologic dressings and subsequently reevaluated. The use
of
cutaneous allografu is a very useful approach when excising facial burns where the goal is to
preserve all possible elements and perform the definitive graffing procedwe on a "tested" recipient
bed. In
cases where an infected
wound is being excised no attempt at placing autograft skin should
be considered until the infection has been resolved following treatrnent with topical and systemic
antimicrobial agents as determined by culture rezults and inspection of the wound.
The choice of the donor site in the perforrnance of a cutaneous autograft
will in some patients be
limited to those skin sites that have not been injured with burns. When there is a choice of donor
sites the requirements of the recipient site and the potential for donor site morbidity should be
factored into selecting the site of graft hárvest. In the grafting of facial burns color match is an
important consideration and obtaining a graft from a site above the clavicles or the inner aspect
of
the thigh will provide the best result. In children harvest of a graft from the scalp results in a donor
site that is not particularly painful postoperatively and has no long-term cosmetic consequences.
The harvest of grafts from posterior body surfaces provides, in general, a more acceptable wound
for most patients. 'While the anterior thigh is an often-selected site it can heal with significant
hypertrophic change and cause a patient more problems and distress than the grafted burn.
j
The use of sheets of autograft skin for resurfacing the burn represents the gold standard. This is the
only acceptable approach for burns of the face and neck and the best choice in grafting of the hands
and breast, Every attempt should be made to use such autografts in children, since they provide the
best long{erm results. It may not be possible to achieve these objectives in patients with extensive
burns or those in whom the pattern and location of the injury limits donor site availability. The use
of meshed cutaneous autografts allows the surgeon to increase the a¡ea covered. Skin graft meshing
devices of various design and manufacture are available with expansion ratios from I : I to I :9. The
wider the mesh the greater the wound area covered, however, it will take the wound longer to close
by in-growth from the margins of the mesh reticulum to
fill
the open interstices during which time
there is the very real potential for graft loss and wound infection to occur- Additionally, widely
meshed autografts have a greater propensity to form hypertrophic burn scars, and may provide a
skin surface with unsatisfactory mechanical stability, inadequate pliability, perrnanenlly poor
cosmetic appearance, and restricted joint mobility. Despite these potential limitations. the use
37
of
meshed cutaneous autografu is an important strategy and potentially life saving approach
in
patients with extensive body surface area burns.
The technique of skin graft harvesting would seem a relatively simple procedwe yet it is often
not
done well. As noted above the harvest site should be the one that will yield a graft with the
desirable characteristics and the least donor site morbidity. Grafts should be of sufficient size to
achieve wound closure with a minimtun of inter-graft seams. Powered dermatomes are available
with up to six inch cutting widths that provide excellent shéets of skin for facial g.fts or when
meshed can cover a significant burn area. Donor site preparation is essential to obtain a uniform
graft- Powered clysis can rapidly be accomplished over an extensive harvest site using an air
powered surgical wound inigating syslem equipped with a 14 or 16 gauge needle attachedto three
liter bags of normal saline. This provides
a stable
uniform surface for graft harvest and limits the
difÏiculties encountered when harvesting over contoured surfaces or bony prominences. The
thickness of the harvested graft should be ¡elated to the site to be grafted, whether the graft is to be
meshed and the mesh ratio, and to some degree surgeon preference. The desired thickness ofthe
graft also influences donor site selection, i.e., a'thick" graft should be harvested from an area of
"thick" skin- Harvest of a "thick" graft from an area of "thin" skin, i.e. the imer arm, can produce
a fi¡ll thickness wound which will have to be graftedSkin grafts through which one can read þrinted material are primarily epithelial autografts with a
minimal amount of dermis (.004-.006 inch) while those, which are more opaque contain a variably
greater amount of dermis (.00S-.012 inch). Thinner grafts yield a better donor site and ñrnction
well on a dermal wound bed but may not do well when placed on a v/ound excised to fascia. In
elderly patients thin grafts which contain insuflìcient numbers of keratinocyte progenitor cells are
considered the cause of melting graft syndrome and prolong the time of re-epithelization. Thicker
grafts are more pliable, heal with less contraction, and will do better than thin grafts when meshed.
The thicker grafts may result in donor site scarring and delay in donor site closure especially in the
elderly patient.
The harvested graft should be placed on the prepared burn wound parallel to the major flexion
creases and can be attached mechanically
with $aples or sutures or secured with tissue adhesives
such as fibrin glue. A properly placed set of grafts on an extremity should at the end of the
operation be able
1o
remain in place aslhe extremity is put through a gentle range of motion- One
38
I
of the most important aspects of a skin grafting procedure is the application of a proper dressing.
highly successful approach is to use multiple layers of
with
a non-adherent
A
linen dressing moistened
a 5olo solution of mafenide acetate applied circumferentially to the excised and grafted wounds
on ari extremity. A bolster produced by using net dressings drawn tightly over the bum dressings
and stapled to the skin is used to
"fix" the grafts on torso wounds. Graft failure
occurs as a rezult
of inadequate excision, inadequate hemostasis, infection, subgraft seroma formation, mechanical
sheering during post-operative care, or rarely, 'bpside down- application. The first dressing change
is typically done 48-72 hours postoperatively.
If
a sheet graft is well intact at that time a non-
adherent dressing is reapplied to protect the wound. In the case of meshed autografts, the moist
dressings of mafenide acetate solution, changed daily or more often as required, are continued
until
the mesh is closed.
Skin Substitutes: V/hile split thickness cutaneous autografts are the usual method of wound
closwe there is often the need for a skin substitute. Altemative wound coverings are used to
achieve wound closure when the available donor surface area is not zuflicient, there is a need to
test the wor¡nd bed, or for primary management of selected partial thickness wounds. The goal with
a
skin substitute is to obtain temporary physiologic wound closure and protect the wound from
bacterial invasion. The two most commonly used naturally occurring biologic.dressings are human
cutaneous allograft and porcine cutaneous xenograft. Human allograft skin is commercially
available as split-thickness grafu in either fresh iiable or cryopreserved form- Both of these
preparations are capable of becoming vascularized however this best occurs with fresh allograft
skin. Allograft skin can provide wound coverage for three to four weeks before rejection.ro2
Xenograft tissue is available as reconstituted sheets of meshed porcine dermis or as fresh or
prepared split+hickness skin. Porcine skin impregnated with silver ions to suppress wound
colonization is also available. Xenograft skin can be used to cover partial thickness injuries or
donor sites, which re-epithelialize beneath the xenograft.r0l
Various synthetic membranes have been developed that provide wound protection and possess
vapor and bacterial barrier properties. Biobrane ru (Dow-Hickham, Sugarland, Texas), is one such
product which has been used in the management of þartial thickness and donor site wounds.roa
This bilaminale membrane consists of a collagen gel adherent to a nylon mesh as the dermal analog
to promole fibrovascular ingrowth and a thin outer silastic film as the epidermal analog to provide
barrier properties. Biobrane has also been used as the scaffold for the growth of allogenic
39
fibroblasts that secrete, while in culture, various growh factors along with other mediators.
The
fibroblasts are then removed by freezing to complete preparation of the membrane. These
membranes are currently approved for use in fully excised wormds, donor sites, and zuperficial
partial thickness burns.¡05 Another collagen-based skin substitute is the dermal replacement
developed by Burke and Yannas, presently in use as lntegraru (Integra Lifescience Corporation,
Plainsboro
NI).
This membrane consists of an inner layer of collagen fibrils with added
glycosaminoglycan and an outer barrier membrane of polysiloxane. It is placed over freshly
excised full-thickness wounds and once fully vascularizedthe epidermal analog is removed and the
vascularized "neodermis" covered with a thin split thickness cutaneous autograft.
¡6 A permanent
skin substitute for burn care victims represents the search for the Holy Grail. Presently, cultured
epithelial autografts are commercially available but are limited in their use because of suboptimal
graft take, fragility of the skin surface, and high cost.to7
.
Use of any biologic dressing requires that the excised wound and the dressing that has been applied
be meticulously examined on at least a daily basis. Submembrane suppwation or the development
of infection necessitates removal of the dressing, cleansing of the wound with
a surgical detergent
disinfectant solution, and even re-excision of the wound if residual nonviable or infected tissue is
present- Following such wound care, the biologic dressing can be reapplied and if it remains
adherent and intact for 48-72 hours without suppuration, that biologic dressing can be removed and
the wound closed defìnitively with cutaneous autografts.
The propermanagement of the patient's bum wounds is critical to achieve the optimum cosmetic
and functipnal outcome and the timely return of the patiatt to full activity.In patients with major
burns the wound must be properly cared for and closure achieved expeditiously to lessen the level
of physiologic disruption that accompanies a major bum. Failure to do so can result in invasive
wound infection, chronic inflammation, erosion of lean body mass, progressive functional deficits
and even death.
The Treatment of Special Thermal Injuries
Electric Injury
The principal mechanism by which electricity damages tissue is by conversion to thermal energyCurrents of 1000 volts and above are classifìed as high voltage. Upon contact with such currents,
the body acls as a volume conductor with small differences in conductivity among tissues of little
40
consequence. At contact points where current density is greatest tissue charring may limit current
flow but
at very high voltages current
flow persists until the contact is intemrpted. The electric
current may induce ca¡diac and/or respiratory arrest necessitating cardiopulmonary resuscitation at
the site of injury, on the way to the hospital, and in the emergency deparhnent- Arhythmias may
also occur after admission to the hospital necessitating EKG monitoring for at least24 hou¡s after
the last recorded episode of arrhythmia.
Two characteristics of high voltage electric injury increase the incidence of acute renal failure in
patients
with such injury. First there may be only
a small charred contact site evident
extensive inapparent subcutaneous tissue injury in a limb underlying unbumed skin
cutaneous injury may lead to gross underestimation of resuscitation
.
with
The limited
fluid needs- Secondly, the
mass of muscle injured by the electric cuirent may liberate large amounts of hemochromogens that
may damage the renal tubules- In addition to the electric injury, arcing of the current may ignite
the patient's clothing to cause conventional thermal bums in addition to the elect¡ic injury.
Resuscitation fluids should be based on the extent of burn visible plus the estimated daily needs
of
the patient and adjusted according 1o the patient's response. If the urine contains hemochromogens
(dark red pigments) fluid should be administered to obtaìn 75-100 ml of urine per hour with
sodium bicarbonate added to the fluids to alkalinize the urine. If the hemochromogens do not clear
promptly, or the patient remains oliguric, 25 grams of mannitol should be given as a bolus and 12.5
grams of maruritol added to each liter of lactated'Ringers until the pigment clears. After
administration of mannitol urinary output is no longer an index of resuscitation adequacy and other
indices of physiologic well being must be monitored to assess rezuscitation status.
ìilhen the body functions as a volume conductor, current flow is proportional to the cross sectional
area of the body part
involved. Consequently, severe tissue destruction may occur in a limb with
relatively small cross section area and relatively little tissue damage occur as current flows through
the trunk. With cessation of current flow body parts that acted as volume conductors now act as
volume radiators with periosseous tissue deep in the limbs being exposed to higher teinperatures
for longer periods of time.ro8 Damage to the muscle in a limb is often associated with marked
increase in the pressure
within the compartment containing the damaged'muscle which,
if
unrelieved, may cause further tissue necrosis. A limb muscle compartment which is stony hard to
palpation should alerl one to the need for surgical exploration. Evidence of extensive deep tissue
necrosis, development of a compartment syndrome, and persislent or progressively severe
4l
hyperkalemia mandate operative intervention. At the time of exploration,
the investing fascia is
widely opened and the muscles ofthe involved limb thoroughly examined
including the
periosseous muscles of the limb which can be necrotic yet
overlain by more superñcial viable
muscle (Fig'8)' The extent of destruction may necessitate amputation
at the time of exploration,
particularly if the nonviable muscle is the source of persistent hyperkalemiaIf the extent of
muscle necrosis in a limb is indefinite, an arteriogram may be helpful.
The
identification of
'þruning" of the intramuscular branches of the arterial tree identifies injwed
muscle and dednes
the level of amputation required to encompass the nonviable tissue-ræ
Following debridement or
amputation the wound should be dressed open. The patient is returned
to the operating room in2436 hours for reinspection and fi:rther deb.ridement of nonviable tissue
if necessary. 'When all tissue
in the wound is viable it may be closed definitively-
A detailed neurologic examination
m-ust be
performed on all patients with high voltage electric
injury at the time of admission and at scheduled 24-48 hour intervals thereafter.
Signs of
peripheral nerve and central nervous system impairment may be evident
immediately after injury or
may aPpear later- It is uncommon for a nerve directly injured by electric current
to regain function.
The immediate functional impairment caused by nondestructive injury to which
motor nerves are
more sensitive than sensory nerves commonly resolves. Late occurring parasthesias
and other
polyneuritic symptoms causing deficits in the function of peripheral nerves
remote from the sites of
electric contact have been attributed to electropohation, the cellular effects
of millivoltage electric
fields-rr0 Immediate neurologic impairments caused by direct nerve damage
of the spinal cord
more commonly resolve than do spinal cord deficits of later onset. Delayed
onset spinal cord
dysfirnction can range from quadriplegia to localized nerve deficits with
signs of ascending
paralysis and even an amyotrophic lateral sclerosislike syndrome.r¡r
Remote organ injury is rare in patients with high voltage injury, but
intestinal perforation, gall
bladder necrosis, and direct liver injury have all been reported. Delayed
hemorrhage from medium
to large sized vessels has been attributed to electric injury induced arteritis
but inadequate
debridement of injured tissue or transmural necrosis of the vessel wall
as a consequence of
exposure and dessication appear to be more likely causes_
The formation of cataracts has also been associated with high voltage
electric injury, particularly in
those patients with a contact sile on thç head or neck. The patient
should be informed that such
42
catarztcts may occur, commonly th¡ee or more years after the injury, but often much sooner-
In
patients witb a head contact site exfoliative debris may be evident in the anterior chamber of the
eye immediately after
injury.
Such debris is slowly clea¡ed and typically requires no specific
treatment.
Tissue damage can also be caused by low voltage house current. Burns of the oral commissure
occur in young children who bite electric cords or suck on the end of a live extension cord or an
electric ogtlet. The lesion may have the characteristics of full thickness tissue damage but early
surgical debridement may only accentuate the defect and should be avoided. These injtuies will
usually heal with minimal cos¡netic sequelae which can be addressed electively
if
needed- In tbe
course of spontaneous healing,labial artery bleeding may occur. The parents should be warned
that such bleeding, which can be impressive, Dây ocçur and instructed in how to apply manual
pressure for temporary control until the vessel can be ligated-
Cardiopulmonary arrest is particularly common in patients struck by lightning and necessitates the
immediate institution of cardiopulmonary resuscitation. Subsequent ECG abnormalities are
uncommon and signs of acute myocardial damage, though rare, may become evident later- Coma
immediately following injury is common, but typically transient. Keraunoparalysis (lightning
paralysis) characterized by parathesias and paralysis typically involving the lower limbs may
develop over several days after ligbtning injury in association with vasomotor disorders-tt2 This
paralysis typically resolves without residual deficit. Lightning injury of the skin is generally
superficial with a "splashed on" arborescent and spidery appearance.rr3 The tip-toe sign refers to
the small, circular full thickness bums on the tips of the toes that are cornmon in patients with
lightning ìnj".y. Prompt institution of cardiopulmonary resuscitation has incre.ased the survival
rate of patients stn¡ck by lightringtoT}Toand improved management of the systemic effectsof
lightning injury has reduced the incidence of acute renal failure and other complications-r2
Chemical Injuries
A variety of chemical agents can cause tissue injury
as a consequence
of an exothermic chemical
reaction, protein coagulation, dessication, and delipidation. The severity of a chemical injury is
related to the concentration and amount of chemical agent and the duration with which it is in
contact with tissue-tto Consequently, initial wound care lo remove or dilutethe offending agent
takes priority in the management of patients with chemical injuries (Fig.9). lmmediate copious
43
water lavage should be instituted while all clothing, including
gloveg shoes, and underwear
exposed to the chemical are being removed. The
lavage is continued for at least 30 minutes
or
until dilution has lowered the concentration of the agent below
that which will cause tissue damage
or until testing the involved zurface with litrnus paper
confirms that the agent has been removed,
For
patients in whom extensive st¡rface injury has occurred,
the irrigation fluid should be warmed
to prevent the induction of hypothermia Although seldom
needed, if a patient with concentrated
alkali injruies requires prolonged irrigation and is hemodynamicalty
stable he can be cared for
while sitting in a chair under a shower-
The appearance of skin damaged by chemical agents can
be misleading. In the case ofpatients
injured by shong acids, the involved skin surface may have a
silþ texture and a light brown
apperirance which may be mistaken for a srmbum rather
than the ñ¡ll thickness injury that it is.
Skin injured by delipidation caused by petoleum distillates
may be dry, show little if any
inflammation, and appear to be rmdamaged but found to be a
full thickness injury on histologic
examination.
variable degrees ofpulmonary inzufficiency may occur in patients
with cutaneous injuries caused
by volatile chemical agents which can also be inhaled, such as
anhydrous ammonia, the ignition
products of white phosphorus, mustard gas and chlorine,
and even the vapors of strong acids.
Additionally, pulmonary insufficiency may be cåused by the inhalation
of the gaseous products
of
petroleum distillates as may occur in patients who sustain
delipidation injuries due to partial
immersiòn in gasoline and other petroleum products.
In the case ofpatients with anhydrous ammonia injury, any powdery
condensate adherent to the
skin should be brushed offprior to inigation. Hydrofluoric (HF)
acid injury is most common in
those involved in etching processes, the cleaning of air
conditioning equipment, patio gri¡s and
other metallic objects with spray products containing HF,
and petroleum refining. After contact
with hydrofluoric acid there is a characteristic pain-free
interval of variable duration with
subsequent appearance of focal pallor which progresses
to penetrating necrosis, typically
accompanied by severe pain- Immediately after injury,
calcium gluconate gel should be applied
topically, or prolonged irrigation with a solution of benzalkonium
chloride instituted- The
persistent severe pain that may occur in digits injured
by hydrofluoric acid can be relieved by
injecting l0olo calcium gluconate inlo the artery supplying that
finger. Local tissue iniecrion of
44
calciurn gluconate is an altemate route of delivery but may in itself compromise the blood supply
of the involved digit. Persistent pain caused by subungual IIF is best treated by removal of the nail
under digital block anaesthesia. The pain typically relents and the nail grows back with little or no
deformity. If these measures fail to control pain, Iocal excision and skin grafting will be needed to
remove the damaged tissue and achieve pain relief.r15 Extensive hydrofluoric acid injury may
induce systemic hypocalcemia which is treated by intravenous infusion of calcium.
Burns caused by phenol should be treated with immediate water lavage to remove, by physical
means, the liquid phenol on the cutaneous surface. Following that lavage, the involved area should
be washed with a lipophilic solvent such as polyetþlene glycol to remove any residual adherent
phenol which is only slightly soluble in water.rr6 Intensive systemic support is required for
patients with extensive phenol burns, in whom absorption of the agent can cause central nervous
system depression, hypothermi4 hypotension, intravascular hemolysis, and even death.
Injuries caused by white phosphorous are usually discussed with other chemical injuries but are
actually conventional thermal burns caused by the ignition of the particulate phosphorus. These
injuries are most commonly encountered in military personnel injured by explosive antipersonnel
devices (grenades) that may cause mechanical tissue damage and drive fragments of white
phosphorus into the soft tissues.
All wounds containing white phosphorus particles should be
covered with a wet dressing which is kept moist to prevent ignition of the particles by exposure to
air. If
the interval between injury and definitive wound care
will
be so long as to permit
dessication of the wet dressings, the wounds can be briefly washed with a freshly mixed dilute 0.5 lolo solution of copper sulfate followed by copious
rinsing. Such treatment generates a blue-gray
cupric phosphide coating on the retained phosphorus particles which both impedes ignition and
facilitates identification.trT Whatever form of topical treatment is employed, the wound should be
debrided and all retained phosphorus particles, which can be readily identified with an ultraviolet
lamp, removed. The removed particles should be placed under water
1o
prevent them from igniting
and causing a fire in the operating room-
Strong acids and alkali can cause devastating ocular injuries and must be treated immediately, even
before leaving the scene of the injury, by irrigation with water, saline, or phosphate buffer. In the
hospital eye inigation must continue until the pH of the eye surface returns to normal. The rapid
penelration of ocular lissue by strong alkalis necessitates prolonged irrigation (12-72 hours)- Such
45
irrigation is best carried out with a modified scleral contact lens with an irrigating
side arm. The
effects of iritis induced by chemical ocular inj,rry a¡e minimi zedby installation
of a cycloplegic
such as lolo atropine following
inigation. If inigation
and removal of the offending agent is
delayed, the entire globe may be so damaged as to lose turgor and all visual
finction.
Even with
early irrigation, corneal damage can be severe and late complications of symblepharon
and
xerophthalmia may occur- An ophthatmologist should be involved in the care
of such patients
from the time of admission.
Bitumen Burns: Bitumen injuries are commonly caused by hot tar coming in contact
with the
skin- The injury that results is a thermal contact burn which is not associated with
any significant
component of a chemically mediated injury. There is no significant absorption of
materials unless
the patient is in an explosion and has ingested or inhaled the material. The primary
initial
treatnent is urgent cooling of the molten material with no attempt made to remove the tar.
By cold
application the lransfer of heat can be limited and the degree of tissue damage minimized.
There
are various agents that have been advertised as being effective for the removal of
tar and asphalt
products. These have varied from mayormaise to simple petroleum-based jellies and seem
to be
simila¡ in terms of efficacy. Considering that the initial temperature of liquid tars and asphalts
are
typically in excess of 600 degrees Fah¡enhèit early concerns about infection would seem to be
unfounded and offer no support for urgent removal with potential destructive consequences
to
underlying otherwise viable tissue. It is preferable to apply an emulsifoing petroleum based
ointment and allow the tar to separate during the first day or two affer admission
rra
Cold Injuries: Injuries occurring secondary to environmental exposure can result in local injuries,
frostbite, or systemic hypothermia. During the wintertime in urban environments, the most
common mechanism of injury involves homeless persons or an elderly patient who has
become
disoriented and wandered from home. The pathophysiology of the local injuries consists
essentially
of crystal formation due to freezing of both extracellular and intracellular fluids. Consequently,
the
cells dehydrate and shrink and blood flow is altered to the exposed area resulting
in tissue death.
During the thawing of damaged tissues, micro emboli rhat have formed further occlude the
microvascular circulation adding insult to injury.rt8 It is important to note that the initial
clinical
presentation of the patient is nol likely representative of the ultimate degree of tissue
loss. patients
presenting with frostbile u/ill have coldness of the injured body parr with loss of
sensation and
proprioception. On initial exam, the limb may weìl appear pale, cyanotic or have a yellorv
white
46
*
discoloration- During rapid rewarming at 4042"C in water for l5-30 minutes, hyperemia will
occur followed by pain, paresthesias and sensory deficits. Over the subsequent 24 hours, edema
and blistering
will
develop and
it may be the better part of a week before one can determine the
true depth and extent ofthe injury.In the initial management of the patient, re-warming is critical
but it must be done only when there is no chance for an episode of re-freezing. If blisters appear
whether they should be preserved or debrided has proponents on both sides of the ariswer. Some
authors suggest that white blisters can be debrided while purplish blue blisters should be left intact.
The injured extremity should be elevated in an attempt to control edema and padded to avoid
pressure-induced ischemia as a secondary inzult. Administration of pain medication is based on the
patient's response- Frostbite wounds are tetanus prone wounds and therefore tetanus toxoid should
be administered based on the patient's immunization status.
Before any definitive plans are made for surgical intervention suflicient time should be allowed to
pass so that a clear demarcation between viable and nonviable tiszue is apparent
(Fig.l0).
However, it is not in the patient's best interest to follow the adage of "freeze in January and
'While
amputate in June",¡re
it will take some time for definitive delineation of the depth of the
injury, once the wounds have begun to mummiff the thought that there will be tissue salvage
seems more than naive. Palients suffering frostbite injuries should be evaluated
for other potential
trauma and treated for systemic hypothermia if it is present. The post-hospitalization disposition
of
cold injury patients requires a clea¡ understanding of their preexisting health status and the factors
that predisposed them to injury such as dementia or major psychological disease.¡zo
Radiation Injury: Radiation exposure secondary to the detonation of
a thermonuclear device is
not as likely as is exposure from an industrial or medical accident, misuse of radiation materials, or
acts of terrorism. The dispersal of radioactive substances can lake several forms including
accidents during storage and mishandling, accidents during transportation of radioactive materials,
intentional dispersal either alone or in combination with other agents, and intentional dispersal
through an explosive device. In both storage and transport accidents, the dispersal and subsequent
exposure to radioactive materials is usually limited to the people immediately involved and is well
contained geographically once the event is recognized. It is lypically difTìcult 1o expose large
numbers of individuals to significant doses of radialion at any given time and the risks are limited
to those involved in a given incident. Small dose radiation exposure does not affect health for
many years and is associaled with few acule problems although it is still a signifìcant health risk.
47
In the event of intentional radiation dispersal, the risk of exposure
and injury as well as the source
involved need to be evaluated- The risk of trauma is related
to the primary explosive device itself
as well as hauma related to the secondary effects of
the explosion such as shell fragments, struchre
collapse, or injury from debris. Psychological trauma due to
either patients witnessing the primary
event or the experience of living through the event with the associated
physical manifestations may
Pose a further problem in the handling of a significant number of injured victims.
Exposure risk is related to primary contamination from the particles
released from the explosive
device, secondary contamination from particles that have become
mixed with debris, debris dust
and fallout, and tertiary contamination from exposure to particles
in contact with patients. Ionizing
radiation is composed of rwo Wpes: radiation that has mass and that
which is energy only.
Exposure to alpha particles which are relatively large, highly charged particles,
slow moving and
penetrate only a few microns into tiszue can be effectively shielded
with ordinary substances such
as paper, cardboard or clolhing. Alpha particles can be a source
of secondary and tertiary
contamination' Beta particles made up of either positively or negatively
charged species have
greater energy and can penetrate more deeply into tissues and
require shielding
with material such
as aluminum to prevent exposure. Both alpha and beta particles
result from the decay of a
radioactive source- Gamma and x-rays are produced by radioactive decay
or an x-ray source; they
have neither mass nor charge however they penetrate deeply and shielding
requires the use of such
materials as lead, steel or thick cement. Following removal from the
source of radiation no
further exposure occurs and the patient poses no danger to those providing
care. Radiation
due
to
neutrons requires special consideration. Nuclear reactors are the major
source of neutron emission
and create radiation that penetrates deeply causing widespread damage
to underlying tissues.
Radiation exposure of two to four gray (Gy) can cause nausea and vomiting,
hair loss and bone
malro\il injury leading to death from infection up to two months after exposure.
Exposures of six to
ten gray result in the destruction of the bone marrow, and inju.y
to the gastrointestinal tract with a
mortality approachingS}%within one month. When the exposure
is ten to twenty Gy there is
severe injury to the gastrointestinal tract and death may occur
in as liule as t\¡/o weeks. 'When
exposure is greater than
ùirty gray, cardiovascular
and nervous system damage occur primarily as
result of hypolension and cerebral edema. There is almost immediate
nausea, vomiting,
prostration, hypotension, ataxia and convulsion and dearh can
occur in a matter of hours. At
present there appears lo be no effective lreatment following
radiation exposure. For treatment to
a
48
be effective, it would need to be given prior to the exposure. In cases of accidental exposure,
treating bone marrow suppression while successfi¡l has notþrevented death, which usually occurs
from radiation pneumonitis, GI tact injury and hepatic and renal fail ,re.r2t'rz
The burn injuries resulting from radiation exposure are usually localized and represent a high
radiation dose to the skin. They appear identical to athermal burn and may present with er¡hema
as
with a firsdegree burn which will heal following some sloughing of the skin. With higher dose
exposures, blisters may occur as with a partial thickness burn and healing occr¡rs in a similar
manner.
'When
the radiation exposure has been significant such as twenty gray, radionecrosis
occurs. If the event leading to the radiation expo$re causes surface contamination,
decontamination needs to be done prior to dealing with the wound. This consists of saline
irrigation of the wound and treatment with standard aseptic techniques. It is not necessary to
excise the wound urgently unless
it is contaminated with long-life radionuclides such as alpha
emitting particles. Patients who have greater than a one gray whole body exposure should be
considered for early wound closure so that the wound itself does not become the site of a lethal
infection.l23
To manage radiation-exposed victims effectively
a
hospital must have a well-organized plan in
place and the appropriate decontamination facility within the emergency room. The goals are to
save the patients
life and to prevent further injury, The decontamination must be done so that the
personnel providing care to the patient do not become exposed. AII contaminated materials must
be carefully handled to prevent contamination of the hospital and its facilities and the public
sewage system.
Toxic Epidermal Necrolysis
(IEÐ:
TEN is a rare life threatening mucocutaneous form
of
exfoliative dermatitis that is often secondary to drug sensitivity. The incidence of TEN has been
estimated at 0.4-1.2 cases per million population per year.rza These patients may give a history
sore throat, buming eyes, fever, and malaise and present with systemic
of
toxicity. Physical findings
can include rash, bullae, and diffuse exfoliation with the large areas of separation having the
appearance of a partial thickness burn. When lateral stress is applied to the involved skin
it
separates at the dermal-epidermal junction, Nikolsky's
sign. The resulting wounds give the
appearance of a wet surface as seen in a second-degree
burn. The mechanism of injury is thought
to be keratinocyte apoptosis induced by interactions betrveen the cell surface death receptor Fas
49
and its receptor FasL or CD95L-I25 Lyle
in
1956 was the first to describes
two entities in the initial
description of toxic epidermal necrolysis consisting of staphylococcal scalded skin syndrome (SSS)
and what today is recognized as TEN.¡26 Staphylococcal scalded skin syndrome is a generalized
exfoliative dermatitis due to infections with staphylococcal organisms. In SSS the lesion is at the
intra-epidermal layer with blister formation followed by desquamation of large sheets of skin with
relatively rapid re-eptheliazation over 7-10 days. The outcome in patients \¡rith SSS is significantly
better than that in TEN patients. In TEN there is necrosis of all layers of the skin and a mortality
between 30 and 40% while u,ith SSS itis3-4Yo. Stevens Johnson Syndrome (SJS) is an entity in
which there is also extensive epidermolysis often presenting with target shaped skin lesions with
differentiation from TEN related to the extent of cutaneous involvement. One current delineation
classifies patients with less than ten to thirty percent cutaneous involvement as SJS and those with
greater than ten to thirty percent as TEN particularly
if it involves oral-genital and ocular
mucosa.r2T Whether SJS and TEN represent the same process differing only in the extent
of
cutaneous involvement and sites affected or are pathologically distinct entities has not been
ansrryered
with any degree of certainty,
Patients \Ã/ith TEN have wound care needs identical to those of patients with extensive seconddegree wounds. They exhibit significant fluid losses and have specialized nutritional needs. Care
of these patients in
a
Bum Center by experienced surgeons has resulted in
a
significant
improvement in outcome.r2t General principles of management in these patients include the
cessation of potential precipitating drugs, the discontinuance of systemic steroids
if recently
initiated, ophthalmologic evaluation, and skin biopsy confirmation of the diagnosis.¡2e
Additionally, systemic antibiotics should be reserved for those cases in which infection is highly
likely-
Replacement of
fluid and electrolytes and provision of nutritional support and aggressive
wound care are critical elements in the care of these patients. Wound care may consist ofthe
application of
a
biologic dressing once all of the nonviable tissue is ñrlly debrided or the use of
silver impregnated dressings (Fig.l
l).
The most frequent mistakes in the care and management
of
these patients are underestimating the extent of the cutaneous involvement, airway compromise,
and not understanding how rapidly these patients can become critically
ill.
To date, the results
of
studies of various modalities that can be employed to control the degree of skin slough have been
too inconsistent to recornmend their general use.
t3o
50
Mechanical Injury: The combination of burn injury and multi-system trauma occurs in up to 4 5% of all burn patients -t3t'7t2 Patients suffering combination injuries are typically male with their
injuries having occurred from a flame ignition during an assault or motor vehicle crash. Victims
suffering a combination of burns and trauma tend to have
a
higher incidence of inhalation injury,
higher mortality, higher Injury Severity Score and longer lenglh of stay despite no differences in
total body surface area burned when compared to patients with only burns. Trauma victims with
burns with an inhalation injury have a near three-fold increase in their mortality ratels Those
victims not surviving their injuries typically are significantly older, have
a higher ISS and a larger
body surface area burn compared to trauma victims with burns who survive their injuries. The
management priorities in patients suffering burns plus trauma must be as for patients with trauma.
Understanding the mechanism of injury is vital in determining the probability of associated injuries
and provides a guide in the work-u.p of the patient.
A formal trauma evaluation should be
performed on all bum victims when the history of the event points to the possibility of combined
mechanisms of injury-
Life-threatening injuries must be promptly treated, fractures immobilized, and the resuscitation
fluid needs ofthe patient should be calculated to include the burn wound mandated needs and
those of the associated trauma. Blood is not part of the initial resuscitation for patients with only
burn injuries but when there is multiple trauma blood transfusions may be necessary in the early
management of the patient. Often the presence of a major bum wound results in the patient being
viewed as having only
a
burn and the standard assessment of a trauma patient is not done. Patients
with impaired neurological status should undergo a computerized axial tomographic scan to rule
out intracranial pathology along with evaluation for a spinal injury. This is particularly important
if the patient jumped fiom a buming building to escape the fire, was injured in an industrial
accident, or involved in a motor vehicle crash. Potential thoracic, abdominal or pelvic injuries
should be evaluated with chest, abdominal and pelvic roentgenogr¿lms as well as with abdominal
CT and FAST examinations. Diagnostic peritoneal lavage may also be used in the unstable patient
to verify the presence of an injury requiring exploratory laparotomy. The nonoperative
management of significant injuries of the spleen or liver requires thoughtful consideration in
patients with a major burn and it maybe prudent to opt for surgical management particularly if the
abdominal wall is extensively búrned. In patients with major long bone injuries, early operative
intervention with stabilization will facilitate the patient's overall management as well as that of the
5l
burn' In selected circumstances, early burn excision with skin graft
wound
closure may be the best
approach to facilitate the operative management
ofthe orthopedic injury.
The management ofpatients with significant burn injuries
in conjunction with mechanical trauma
requires a highly coordinated plan of care- The patient
must be continuously reassessed to avoid
missing an injury and the surgeon vigilant to the development
of trauma related complications.
Metabolic and Nutritional Support
Estimation and Measurement of Metabolic Rate
Burn injury alters central and peripheral thermoregulatory
mechanisms, the predominant route of
heat loss' the distribution and utilization of nutrients, and
metabolic rate. All of these postburn
metabolic changes must be considered in planning the metabolic
support and nutritional
management of the hypermetabolic burn patient necessary
to minimize loss of lean body mass,
accelerate convalescence, and restore physical abilities.
Metabolic support includes patient care
procedures and environmental manipulations in addition
to the provision of adequate nutrition.
The percèived temperature of comfort of burn patients (on average
30.4.c) is higher than that of
unburned control patients and necessitates maintaining the ambient
temperature at that level in the
patient's room to prevent the imposition of added cold stress
which would exaggerate an already
elevated metabolic rate-¡33 Physical therapy with active
motion to the extent possible and passive
motion to stretch muscles in the absence of spontaneous motion
is instituted on admission
to
minimize muscle wasting secondary to disuse. Analgesic and
anxiolytic agents should be used as
needed to prevent pain and anxiety-related increases in
circulating catecholamine levels which can
further increase metabolic rate. Assiduous monitoring is necessary
to facilitate early diagnosis and
prompt treatment of infections and thereby reduce their
metabolic impact. The importance of
excision and grafting of the burn wound, has been emphasized
by recent studies showing that such
treatment reduces resting energy expenditure in burn patients,
even if the entire wound cannot
be
excised and grafted at a single sitting.
Even though metabolic rate can be reduced by pharmacologic
means, studies indicating that the
hypermetabolic response to burn injury is wound directed
speak for meeting caloric needs rather
than reducing nutrient supply 1o the burn wound by pharmacologic
intervention. one must
determine the resting energy expendilure in order to calculate
the nutrients required to meet the
52
patient's needs. Bedside indirect calorimetry is the most accwate means of ¿"t"r-irr¡ng
metabolic
rate, but a bedside metabolic cart may not always be available. A number of formulas permit
one
to make close approximations of daily energy expenditure in a variety of surgical patients. A
formula based on studies of extensively burned patients is useful in estimating bum patient calorie
needs,l3a
EER = JBMR x (0.89f42 + 10.01335 x TBS)I x
EER
:
BMR:
TBS:
m2 x 24
x AF
estimated energy requirements
basal metabolic rate
total bum size
m2 = total body surface area
in square meters
AF:activityfactor of l.Z5 forbums
4'*
A rule of thumb estimate for nutritional needs ofpatients whose burns involve more than 30yo of
the body surface is2000-2200 kilocalories and 12-18 grams of nitogen per square meter of body
surface per day.3e
Nutritional Support: Meeting
the metabolic needs of the bum patient can be accomplished by
providing nutritional support via the gastrointestinal tract or by the intravenous route. After
determining what the metabolic needs will be for an individual burn patient the next question is
will
the patient be capable of meeting the needs by oral intake? In patients who can eat
Iikely that
a standard hospital diet
will
meet the calculated needs and
it is not
it is often necessary to
supplement the patient's intake with various nutritional supplements. A calorie count should be
recorded to verifo that the patient is capable of consistently meeting the daily nutrient intake goal.
In the patient who is incapable of achieving the necessary nutrient intake or cannot eat, one must
decide how to deliver the feedings. Total parenteral nutrition in the past provided a way by which
patients could receive the majority or all of their calorie and protein needs but at present has largely
been supplanred by the use of enteral nutritional support. As compared to total parenteral nutrition,
enteral nutritional support is technically easier to accomplish,lower in cost, supports the health
of
the gastrointestinal tract, and ameliorates the systemic inflammatory response syndrome.l35, tt6.t17.
¡18. r39
At the time of admission, a palient who will require specialized nurritional support should have
either a nasogastric or nasoduodenal lube placed- Patients can safety and effectively be fed by
53
either of these routes with appropriate precautions. It is not required that one use custom made
feedings to meet the patient's nutrient needs. It is possible by using combinations of currently
available commercial products to obtain the necessary blend of nutrients, feeding density, water,
and protein requirements while avoiding the cost of compounding specialized enteral feedings.
It is
preferable to start enteral feedings soon after the patient is admitted. The patient should be fed
with the head of the bed elevated to
300
with feeding residuals checked frequently to avoid gastric
distention and possible aspiration. A potential advantage of early enteral feedings is modulation of
the hypermetabolic response although the actual ability of early feedings to achieve this goal has
'When
been called into question. ¡40' r4r' r42
feedings are initiated early post-injury the desired rate
of adminishation can typically be reached within twenty-four to forty-eight hours of admission.
There are multiple recommendations regarding the initial concentration, rate, incremental increase
and the frequency of the increases. Starting a tube feeding of standard concentration at twenty to
forly ml per hour and advancing the rate
a
similar amount every four hours works well in most
patients. The most important issues are that the nursing staff understands the goals, knows how to
monitor for feeding intolerance, and appreciates the attention to detail necessry to achieve
consistent delivery of the feedings.
If a patient is intolerant of gastric feedings and gastric
aspirate volume exceeds the total of two
hourly feedings, the administration of metaclopramide will often resolve the problem. If the
patients fails to respond to metaclopramide an attempt should be made to place either a
nasoduodenal or nasojejunal feeding tube, which
will minimize this feeding difliculty
the risk of aspiration. Patients who become septic
will often manifest
changes
and lessen
in feeding tolerance
along with new onset hyperglycemia or changes in insulin needs as early signs pointing to this
problem. In patients receiving central vein alimentation the risk of catheter sepsis must be
evaluated as an etiology for the patient's septic process. In patients who become intolerant
of
enteral feedings or develop gastrointestinal complications that prevent use of the gastrointestinal
tract, total parenteral nutrition ì¡rill be required. However, with careful attention to detail and a
well designed, patient specific enteral feeding protocol, this should rarely
be needed in the care of a
burn patient.
Monitoring: The complications
associated with the use of enteral or parenteral support in the burn
patient are in large part similar. Burn injury induces insulin resistance which may lead to
hyperglycemia. The mainlenance of blood glucose values with aggressive insulin replacement has
54
uìíoruUt" impact
on the ourcome of critically
ill patienr.ra3 I'l critically ill
patients the preferable
route of administration of insulin is intravenously with the goal ofmaintaining plasma glucose
values between 80-l l0 mg/dl. There is a well-recognized limit to the caloric load that a critically
ill patient
can tolerate from carbohydrates and for the 7O-kilogram patient this is approximately
1800 kilocalories per day from glucose.t4 Excessive amor¡nts of glucose can result in RQ values
>l
which may cause hepatic steatosis and complicate ventilatory management.
Sufficient protein to meet metabolic demands must be provided. To estimate protein needs twentyo/o
four how urine ruea nitrogen is measured to which an additional 0.1-0-2-gm of nitrogen per
TBSA burn remaining is added- These determinations can be done on a weekly basis unless there
been done to determine
is a special need to perform them more frequently. Numerous studies
þave
patients
precise protein ngedq and the optimum bal¿ince of protein to nonproteih calories. In adult
1.5-2.0 g of protein per kg lean body mass per day is a reasonable goal and for children 39
protein per kg lean body mqsl.
ta5' 14ó
¡
of
nonprotein calorie to nitrogen ratio of 100:l provides the
patient with sufficient calories to zupport protein synthesis in the face of ongoing protein
levels has
breakdown and reduces net protein loss.taT,lat 11r" provision of dietary protein at these
level must
shown to positively impact patient outcome.lae An increasing blood urea nitrogen
been
to avoid uremia
be evaluated in terms of nitrogen over feeding and the protein load recalculated
transferrin and
and an associated diuresis. Measu¡ements of visceral proteins such as serum
patient's
albumin can be used to monitor the impact of the nitrogen content of the diet on the
are
nutritional status. Those proteins are simply markers that can be followed over time and
a halfprobably best utilized in a trend analysis based on weekly determinations since albumin has
and
life of twenty days and transferrin eight days. Thyroid pre-albumin with a halÊlife of two days
in
retinal binding protein with a twelve hour halflife can be used to track short-term responses
selected patients.
the diet
To prevent the development of essential fatfy acid deficiencies, lipids must be included in
per
but should not exceed more than 40% of the total calorie load or more than 3 grams per kg BW
day. Most enteral diets will contain adequate fat to prevent the development of essential fatty acid
deficiency and parenteral diet formulations typically contain long chain fatty acids- The serum
triglyceride concentration and the triene/tetraene ratio should be measured weekly to assess fatty
acid status. If that ratio is greater than 0.4 an essential fatty acid deficiency exists which
55
necessitates adjusÙnent of the dietary fat content.r50 Supplemental
medium chain triglycerides can
be given enterally but are associated with increased ketone production
and may cause diarrhea.re
Complications: Serum electrolytes must be monitored to make necessaС adjustnents
in the
amount of free wate¡ sodium, chloride, potassium, phosphorus, calcium and
magnesium provided
to the patient- Laboratory values should be obtained at initiation of the feedings
and daily druing
the stabilization phase and with each change in the patient's clinical status. During
the first several
days after admission, and with the initiation of nutritional support, there can be dramatic
shifts in
semm and plasma values of electrolytes and minerals. As noted above, hypernatremia
can develop
if free water replacement is insuflicient to account for insensible water
loss through the burn
wound, which can be 2.0-3.1mykg body weight/%burn/day-tir Hypernatremia ca¡r
also develop
with persistel-!þbrile eþisodes if free water replacement does not match the patient's
needs.
Hyponatremia may represent under replacement of sodium but typically is related to free
water
excess. Correction of hyponatemia should be attempted with restriction of free water
intake.
In
adults an increase in body weight of more than 400 grams per day reflects water loading
and should
prompt a review of fluid intake and ouþut records and adjustment of fluid adnünisbation.2
Potassium and phosphorous must be given to meet the patient's needs which often exceed initial
estimates particularly when large loads of glucose are being given along with exogenous insulin.
In the course of the patient's care as the open wo'und area decreases and the hypermetabolic state
slowly resolves, the nutrient load should be adjusted so that balance is maintained between
metabolic needs and substrates delivered and the patient is not overfed. Alternatively, if a patient
is
found to have lost more than l0% of hislher admission weight, it is likely that caloric estimates
are
not being achieved or \ryere under estimated. While most experienced clinicians possess the
skill to
assess patient needs accurately the performance of bedside indirect calorimetry
can provide
objective information as to the patient's resting energy expenditure, respiratory quotient,
oxygen
consumption and carbon dioxide production. The results may indicate the need to
adjust the total
calorie load if the resting energy expenditure has been under-estimated or modifr
the ñ¡el subshate
load if the respiratory quolient is approaching or greater than one-
The patient should receive increased amounts of vitamin C, at recommended
doses of a gram per
day in adults and 500 mg- per day in children. which will aid in wound healing.ri2
In patients with
56
bums of greater than}}Yo of the total body surface areannc at doses of 220 mg/day will support
wound healing as well as white cell function-ls3 The routine provision of these nutrients avoids
complications related to insufücient delivery and obviates the need to measure their levels in the
patient.
In patients with prior sugery or preexisting medical conditions special attention may be required to
monitor for feeding intolerance and to insure that adequate amounts of iron, folate and vitamin Brt
are being effectively delivered- In patients who have received extended courses of broad-spectrum
antibiotics vitamin K replacement beyond standard recommendations may be required to avoid the
development of nutritionally related coagulopathy. The preservation of lean body mass requires
nrore than just the appropriate amounts and blend of nutrients. Physical activity is important in
directing the nutrients to muscle and reducing truncal fat deposition and the risk of hepatic
steatosis.
In addition to providing appropriate calorie, protein and nutrient loads to burn patients, it is now
possible to modulate the metabolic response. Administration of beta antagonists in children has
been shown to be safe and have a signif,rcant positive effect on outcome.rso The administration
of
growth hormone, which is depressed following burn injuries, has met with va¡iable results.
Hemdon et al have reported
a
positive effect in burned children given growth hormoners5 but a
recent multi-centertrial from Europe in critically ill patientsshowed an increased mortality in
treated patients.rs6 An altemative strategy that seems not to be associated with problems in adults
and is efficacious in children is the use of the drug oxandrolone, although a recent study reported
that the agent was associated with prolonged need for mechanical ventilation in trauma patients.l5T'
r58, t5e'
t@ Additional strategies that might be utilized are the provision of selected nutrients in
increased amounts. Glutamine, arginine, nucleotides and omega-3 fatty acids have all been used in
attempts to improve immune function above that seen wilh the optimal use of standard nutritional
formulations.r6r't62'r63't64'r6s The routine use of these measures requires a
full understanding of the
therapeutic benefits and the potential adverse consequences of each- Additionally, some studies
have found such supplements to be ineffective.ró6
In patients who have established chronic renal failure or develop renal insuffìciency during their
course of care, changes in the nutritional formulalion will have to be made to accommodate their
altered clinical status. In patients who require dialysis, the frequency of dialysis should be adjusted
so thal the protein inlake needed to rneel metabolic needs can be given. In patients
57
with signifìcant
injuries who are receiving large amounts of feeding through the gastrointestinal trac!
the health
the GI tract itself must be continuously monitored. The development of major gastrointestinal
of
complications while not common can adversely impact the patient's outcome. Complications
can
include ischemic necrotic bowel diseasg intestinal obstruction, the development of closbidium
diffìcile colitis and non-infectious diarrhea.
167'168' r6e'
ræ'rtt The patient's
clinical status should be
continuously monitored and any changes in abdominal findings on physical examination
should be
aggressively followed up with appropriate diagnostic radiographic studies, endoscopy,
stool
cultures and abdominal exploration before the patient deteriorates and develops an irreversible
condition.
TRANSP ORT^A.TION AND TRANSFER
Many important advances have been made in the care and management of bum injrned victims
during the past 50 years. One of the more significant advances has been the recognition of the
benefits of a team approach in the care of critically injured burn patients. The American College of
Surgeons and the American Bum Association have developed optimal standards for providing burn
care and a bum center verification program that identifies those units that have undergone peer
review of their performance and outcomes- Patients with burns and/or associated injuries and
conditions listed in Table
II
should be referred to a burn center.
Once the decision has been made to transfer a patient to a Burn Center, there should be physician-
to-physician communication regarding the patient's status and need for transfer.¡z Institutions
should have pre-existing inter-hospital transfer policies in place to facilitate communication a¡rd
patient transfers. It is critical that the patient be properly stabilized in preparation for the transfer.
The flight transfer team should have the capability ofproviding the care required for a critically
injwed, severely burned patient throughout the entire transfer procedure. A surgeon, a respiratory
therapist, and a licensed practical nurse, all experienced in burn care comprise such a team for long
distance, fixed wing aircraft transfers. For short distance transport by rotary wing aircraft,
inclusion of
a burn physician
in the flight team optimizes the safety and quality of care
of
extensively bumed patients, but patients with lesser burns may be adequately cared for by nonphysician helicopter flight team members (a flight nurse and/or an advanced paramedic) who are
in
ready conlact with medical control- A flight leam roster should be maintained and published
so the
surgeons and other members of the team rvill be available when needed. Physicians and other team
members should be assigned to the flighr (lransfer) leam only after six to twelve months experience
s8
at a bum center which
will
enable them to become familiar
with the complications that occur in
bum patients during resuscitation and develop competence in the prevention, treatrnent, and
resolution of those problems-
D¡ring transport the need to perform life saving interventions such
as endotracheal
intubation or
reestablishing vascular access may be very diffìcult to accomplish in the relatively unstable and
limited space of a moving ambulance or
a
helicopter in flight (Fig.l2). That difficulty makes it
important to institute hemodynamic and pulmonary resuscitation and achieve "stability" prior to
undertaking transfer.by either aeromedical or ground transport. A secure large-bore intravenous
cannula must be in place to permit continuous fluid resuscitation. Patients should be placed on
l11%oxygen if there is any suspicion of carbon monoxide exposure. If there is any question about
airway adequacy an endotracheal tube should be placed and mechanical ventilation ingitr¡ted
before transfer begins- In-flight mechanical ventilatory support can be provided by a transport
ventilator with oxygen supplied from a lightweight kevlar tank hansported in back-pack fashion by
of the
the respiratory therapist. Patient safety dwing transport may necessitate chemical paralysis
patient to prevent lqss of the airway or vascular access. In-transit monitoring for helicopter transfer
includes pulse rate, blood pressure, EKG, pulse oximetry, end tidal C0 , levels, and respiratory
the
For long distance transfer, the same physiologic indices should be monitored' In addition'
rate.
all four
ultrasonic flow meter should be used to assess the presence and quality of pulsatile flow in
a need
limbs on a scheduled basis and excursion of the chest wall should be monitored to identiff
for limb or chest escharotomy respectively- The hourly urinary output should also be monitored
with fluid infusion adjusted as necessary. All patients should be placed NPO and those with a
greater than1¡Tobody surface area burn require placement of a nasogastric tube- In essence, a
mini ICU should be established for the duration of the long distance flight'
topical
The bum wound should be covered with a clean and/or sterile dry sheet. The application of
antimicrobial agents is not necessary prior to transfer, since they will have to be removed on
admission to fhe burn center. Maintenance of the patient's body temperature is vital-
l/et
dressings which can lead to hypothermia, particularly in small adults and children, should be
avoided. The patient should be covered with
a heat
reflective space blanket to minimize heat loss.
pain medication is given in sufficieni dosag. to control the patient's pain during transport while
avoiding respiratory depression, airway comprise or hypotension. Burn wounds, as tetanus prone
wounds, mandate immunization in accordance with the recommendalions of the American College
59
of Surgeons. As in the case of the transfer of any trauma victim, documentation must be thorough,
flow
sheets should be clearly marked, and a
listing of all medications, including IV fluids that have
been given must be provided to the receiving physician. In the case of a patient suffering from
significant multi-system lrauma and burn injuries, it may be necessary to treat the patienfs life
threatening mechanical injury prior to transfer if the transpod time \¡rill b€ of long duration or the
patient is unstable.
et
Survival Data
During the course of the past half century, early postburn renal failure as a consequence of delayed
and/or inadequate rezuscitation, has been eliminated and inhalation injury as a co-morbid factor has
been tamed. Invasive burn wound sepsis has been controlled and early excision with prompt skin
grafting and general improvements in critical care have reduced the incidence of infection,
eliminated many previously life threatening complications, and accelerated the convalescence
of
burn patients.ræ All of these improvements have significantly reduced the mortality of burn
patients of all ages. At the mid-point of the last century, a burn of 43%o of the total body surface
would have caused the death of 50 of 100 young adult patients (15-40 years) with such bums.
Since that time, the extent of burn causing such
50%o
mortality (the Ldo) inZl-yearold patients
has increasedto 82o/o of the total body surface and in 4O-year-old patients to 72Yo of the total body
swface. In children (0-14 years) the L,\o has increased from 5l% of the total body surface in the
1950s to 72Yo today, and in the elderly
body surface area lo
46%o
(Table
(>40 years) the
V). Not only
LAoo has increased
from 23% of the total
has survival improved, but the elimination of many
life threatening complications and advances in wound care have improved the quality of life of
even those patients who have survived extensive severe thermal injuries.
bapldc/04190
60
Legends
Figure 1: The burns on this
abused child show the typical distribution (feet, legs, posterior
thighs, buttocks, and genitalia) of injury caused by intentional immersion scalding. Note the pink
to red color and moist surface of the partial thickness injuries on the proximal legs and distal
thighs. The pallor, hemorrhagic discoloration, and escha¡ caseation of the full thickness injuries
of the feet and distal legs are cha¡acteristic of third degree bums which required skin grafting for
closure.
Figure 2: Diagram of the skin, adnexq and subcutaneous tissue showing, by stippled shading,
the depth of tissue injury that defines both first degree and second degree partial thickness br¡rns
and third degree full thickness burns.
Figure 3: Example of a form used for documenting extent of burn. Figure outlines are filled in
with a blue pencil and a red pencil to indicate distribuiion of partial thickness and full thickness
bums respectively. Note the columns indicating how the percentage of total body surface area
represented by bod¡ part surface changes with time.
Figure 4: The dashed lines indicate the prefened sites of escharotomy incisions for the limbs
(mid-lateral and mid-medial lines), thorax (anterior axillary lines and costal margin), and neck
(lateral aspect). The thickened areas of the lines on the limbs emphasize the importance of
carrying the incisions across involved joints
Figure 5: Endoscopic view of a bronchus in a patient with severe inhalation injury. Note bright
white areas reflecting light from edematous mucosa, erythema and focal ulceration of other areas
of the mucosa and the extensive black carbonaceous material from the smoke deposited on the
endobronchial surface.
Figure 6: Microbial control can be achieved in partial thickness burn wounds by application of a
'When in
polyethylene mesh coated with a nanocrystaline film of pure silver ions as shown here.
contact with wound fluids, the silver is released continuously to limit bacterial proliferation on
a¡rd in the worurd.
Figure 7: A topical antimicrobial cream is applied to the entirety of the burn wound as shown
here after the daily wound cleansing and inspection procedure. The topical agent is reapplied l2
hours later to maintain microbial control-
Figure 8: High voltage electric injury caused the edema evident in the muscles bulging above the
edges of the fasciotomy incision on the forearm and dorsum of the hand. Note the focal areas of
charring on the exposed muscle (white arrows), the deep injury and fixed flexion of the thumb,
index finger, and long finger, and the burn in the anticubital area caused by arcing (black arrow).
Figure 9: Failure to remove footwear and institute water lavage to dilute and remove
concentrated lye, which had spilled into the boot of this patient, resulted in severe tissue injury
during transportalion to the hospital- Note extensive Iiquefaction of tissue, thrombosed vessels
(white arrow), and edema of the extensor tendons exposed at the mid-metatarsal level on
the
dorso-medial aspect of the foot (black arrow).
Figure l0: Spontaneous healing of frostbite injury proximal to the discolored skin on the dorsum
of thìs foot is indexed by decreased hair growth in that area. The demarcation of nonviable tissue
shown here permitted amputation at a mid-foot level and salvaged the heel pad.
Figure 1l: The back, buttocks, and upper thighs of this patient with toxic epidermal necrolysis
(TEl'Ð have been covered with a translucent collagen-based skin substihfie;Biobran@ foilLwing
cleansing with saline and gentle debridement of exfoliated epiderrnis. Note focal a¡eas of
adherent darkly pigmented epidermis which were left in place and covered with the bilaminate
membrane which provides barrier function, reduces pain, and prevents dessication of the exposed
dermal surface to promote healing. The undressed wounds of the arms and legs were covered
with Biobrane@ after this photo was obtained.
Figure 12: The transfer of patients to burn centers is often done by helicopter as shown here.
Note the shiny metallic inner surface (black arrow) of the "space blanket"ln which the patient
has been wrapped to conserve heat and prevent excessive cooling druing transport. The br¡m
surgeon and bum nurse, sitting adjacent to the patient, monitor urinary output and, as needed,
adjust the rate of infusion of the fluids suspended above the patient. The vibration, noise, poor
light, and limited space which conspire to make monitoring and therapeutic intervention difficult,
mandate preflight physiologic stabilization of each patient who is to be tra¡lsfered.
bapldcJ04l90d